Photoflash lamp



- Feb. 3, 1942. M. J;'N. DE MARGITTA 2,272,059

PHOTOFLASH LAMP Filed Jan. 26, 1940 ATTORNEY and drawing in which:

Patented Feb. 3, 1942 I UNITED STAT ES-PAT *QFF C Michael J.: Neuniann de Margitta, New York, N. Y assignor to vWestinghouse Electric in Manufacturing Company, East Pittsburgh, Pa.,

' a corporation of Pennsylvania ApplicationJanuary 26, 1940, Serial No. 315,738

, I I InHungary August'19, 1939 I 9 ma e This application is a continuationQin-partof my prior applications for improvement in 'Flashlamps',,Serial No. 298,276, filed Octgffi, 1939; and

Serial No. 302,023, filed ocean, 1939.-

The invention relates: to lamps andespecial ly to photographic flashlamps. H An object of the invention is to provide a container for a flashlamp thatwill not if the container explodes. Another object of the invention is to provide a flashlamp that will give. a greater intensity of i light without any dangerous bulb explosion.

Figure 1 is a front view, partly in elevation and partly in cross-section of a preferred embodiment of the invention, I V v Figure 2 is an underneath view looking at the bottom of Figure 1. A

Figure 3 is a cross-sectional view of the flashlamp of Figure l on line III-III thereofland showing said flashlamp in combination witha reflector.

Figure 4 is "across-sectional vviewof a -flash-- lamp with an inner reflecting surface. l a

Figure 5 is a modification, especially oi the en-- velope, of Figure 1. I II I Figure 6 is a bottom view of the modification shown in Figure 5.

Figure '7 is a still further ures1and5. 7

Figure 8 is a bottom view of Figure 7; I Figure 9 is a view, partly in crosssection and partly in elevation of a screw type base asfapplied to Figure 1. I I a V Figure 10 is a modification of the envelope of Figure 7.

modification of Fig- Figure 11 is a front elevation of' a j acktype base supplied to the flashlamp;

Figure 12 is a view, partly in elevation and partly in cross-section, of a modification of the. lower portion of the embodiment of Figure '1.

one wall is parabolic. I A Figure 16 is a cross-sectional, view of a modification of the base Figure -1 with a leak indicator member included. I I H Commercial flashlamps co prise a bulbor en- I danger from exploding glass. 'I'hese' glass lamps be dangerous I velope of clear glass, It isapparent, becauseof the ignition of eombustible material within this glass envelope, that there is always present a mustbe carefully handled on account of danger of glass nbreakage. The bulging glass casing and package protection therefor makes diiilcult the transportation of a quantityof'lamps in ones pocket. v I

It is one of theobjects of my invention to elimmate the glass envelope and thus remove the danger-of flying glass in the use of flashlamps. I At th same time the size of the casing is reduced sothat a numberof lamps may! be carried in a pocket. I It is alsoan object of my invention to provide a more intense flash of light which I accomplish by utilizing a pressure of active'gas such asloxygen within the flashlampcontainer at a pressure higher inside pressure would scatter the glass if I greater than atmospheric. For such use a glass container would be very dangerous because the the glass shouldcrack. I I I I .I also desire, at the same time, toprovide a very cheaply manufactured photoflash'lan' p-and, at the same time,-to reducethe size so that a large number of flashlamps may be conveniently carried. I accomplish these objects by making'the container of a flashlamp of organicematerialof suitable translucence or transparency with ade- I quate elastic and plastic properties. These ma- 7 terials comprise one or more of the class designated as plastics. These plastics preferably have a softening .point somewhere between and "3009 F. and also a heat =capacity,'heat transfer and heat conductivity and dissipation so; that there will beno explosion of the materiallthat lucent plastics of the various resins such as ureal formaldehyde and phenoliormaldehyde 'may be used as well as those of the other plastics group of casein, pyroxylin, shellac and rubber. Some of Of course, other shapes maybe utilized suchas a' square, triangular, oblong or other configuration.

7 the suitable'plastics .are sold under theftrade- Plastacell, Plexi gias's,

names of ,Lucite, Bakelite BT-48-005."

preferably comprises a closed end tubular mamher In of a" plastic such as cellulose, acetate, or

one of the other plastics previously mentioned.

Across the open end of this tubular portion is a disc Ii, having two conductors i2 and I3 sealed therethrough. This disc il may be of the same or other material than the tube ill. The material, however, should be capable of being sealed or cemented substantially vacuum tight at the periphery l4 of the disc to the flange ii at the edge of the tube I0. Igniting means l6, such as a filament coated with zirconium, aluminum or phosphorous powder, is connected across the inner ends of the two conductors l2 and [3. The top of the disc may be coated with a reflecting coating or beopaque white so as not to absorb light energy.

Within the tube Iii is a combustible material H, such as foil or fine wire of aluminum or magnesium, which is capable of being quickly ignited by the igniting means It. Also within the con-' tainer is a combustion supporting gas such as oxygen. The pressure of this gas is preferably in excess of atmospheric pressure and may be as much as 10 atmospheres. This additional presa sure of oxygen provides a very intense flash of light when the metallic filling I1 is ignited. The

size of the lamp can be made smaller. With higher pressures of oxygen, the thickness of the casing l0 may be of the order of a sixteenth of an inch. With oxygen at atmospheric pressure, the thickness of the casin may be as thin as .02 to L005 inch.

The flash bulb may be located in front of a curved reflector at l8, as illustrated in Figure 3. It is not necessary to. utilize a separate reflector, and a reflecting surface i9, preferably of nickel or aluminum, can be placed upon a portion of the walls of the tubular portion ID, as illustrated in Figure 4.

While this reflector could be placed on either I the outside or inside of the container, I have illustrated it on the inside wall in Figure 4. This surface may be a member moulded in the inner wall if desired.

In Figure 5 I have illustrated longitudinal ribs 20 on the casing ill for strengthening purposes in case a thinner wall or a higher pressure of gas is utilized. These ribs may also be transverse as indicated at 2| in Figure 7.

In Figure 5 I have also illustrated a modification of the base which may be applied to other types of fiashlamps besides the particular one illustrated in the figure. The light weight of the casing and the small size permit small and cheap base construction disclosed in this and other figures.

The base comprises two layers, 22 and 23, of plastic material, the upper one having two holes 24 and 25 for the passage of the conductors 26 and 21 from the igniting device 28 through this first layer of plastic. These wires are then bent to the outside and the second disc 23 applied thereto. The ends 28 and 29 of these wires are then bent around the lower disc 23 and the assembly sealed by pressure or heat or both to the flange l5 of the container. Cement may also be used. The pressure and heat applied will embed the wires 26 and 21 in and between the two discs. These wires can be of very cheap flexible conducting material because of the lightness of the lamp, and the construction affords a very easily assembled device.

In Figure 7, the container'lfl preferably does not have a flange around its periphery 30. The sealing member is preferably a dish-shaped member 3|, and the two wires 32 and 33 connected to the igniting means 34 are compressed between the periphery 30 of the tube It and the sealing member 3|, by pressure or heat or both.

In case, however, it is desired to utilize a screw-threaded type base as commercially applied to illuminating lamps, the structure illustrated in Figure 9 can be utilized. The conductors 34 and 35 pass through the disc member II and one of these wires, such as 34, is connected tothe metal screw-threaded portion 36, and the connection 35 extends to a metal tip 31, projecting from this screw base 36, and insulated therefrom by insulation 38.

The jack type connection of the base is illustrated in Figure 11, wherein one conductor is connected to the conducting ring 39 insulated by '40, from the tip 4| connected to the other conductor.

A still further modification of the invention is disclosed in Figure 10, wherein the conductors 42 and 43are molded in the plastics disc 44 and then the ribbed casing I 0 is sealed thereto, by having its periphery 45 pressed or heated or both, to the edge of this disc. Cement may also be used. It will be noted that the wires 42 and 43 have a considerable portion of their length within the disc 44 so that they may be adequately supported therein, and also to provide widely spaced outside contacts. The use of this disc 44 in Figure 10 also'permits the use of a tubulation 46 for exhausting the container and filling it with the desired gas.

It will be noted that the use of plastics for the casing i0, permits a short and wide diameter casing, as illustrated in Figure 10, as well as the long type casing, illustrated in Figures 1, 5, and 7.

In Figure 12 I have illustrated a base 41 with conductors 48 and 49 sealed therein, which base 41 may be screw-threaded as'at 50, into the periphery of the casing I0, after the casin has been filled with the combustible material i1 and the gaseous filling.

In case the screw threads are not sufliciently vacuum tight, heat might be applied to the outer portion of the base to make the material flow into a homogeneous mass. Cement may also be used. v Because of the ready adaptability of the plastics to various shapes,I can utilize a wall of parabolic cross section 5|, as illustrated in Figure 13, wherein another integral wall 52 is slightly curved to provide a slightly divergent light path for the light. This parabolic wall 5| can, of course, be coated with a reflecting surface, such as 53. While in Figure 13, I have illustrated the cross-sectional wall as being integral, it is, of course, apparent that the wall can be of the two parts 54 and 55, illustrated in Figure 14. The slightly curved wall 55, may have certain portions 56 of prism-like extensions in case it is desired to focus the light flash similar to the focusing of the light from automobile headlights.

It is also within the scope of my invention to provide a metallic reflecting parabolic member 51, illustrated in Figure 15, with a front plastics closing member 58, sealed thereto. While I have described the various types of lamps illustrated on the drawing as adapted to contain a gaseous atmosphere at higher than atmospheric pressure, it is apparent that the forms of these lamps maybe also utilized with a gaseous fllling of'one atmosphere or less.'

In Figure 16 the base II has a central opening 60 covered with a flexible membrane 6| which may also be of a material, such as the plastics previously mentioned, strong and air- 7 heat generated in its proximity.

generated on the surface is increased, .the cross- 1 increased oxygen pressure.

tight enough to hold the gaseous atmosphere of the lamp and yet flexible enough to bulge out. into the opening of the hole under the higher 7 than atmospheric pressure within the casing."

If a leak occurs, this bulge will flatten and indicate a defective tube. With" lamps' containing atmospheric as wellv as above atmospheric 'pressure, the thinner member i l proves a safety valve for'letting out gas pressure when an excess Y of pressure occurs that might crack the bulb II.

The breaking of such a membrane would also indicate that the bulb had been used. Instead of a separate membrane, the wall of the lamp could be made thinner and weaker at a desired location.

Various'well-known commercial cements may ducing light within andfemanating from said containerysaid gas pressure tending toretain' the container inflated to maximum volume and obtaining increased light intensity upon ignition. I

. y 3. A lamp comprising alight-passing'seli-supporting sealed container from the group of organic plasticscharacterized bytranslucency and flexibility, said container having therein a combustible metal and a combustion-supporting gas at substantially mo'refthan' atmospheric pressure within said container, andmeans tor instigating combustion'ot said metal, said gas pressure tending to retain the container inflated to maximum volume and obtaining increased light intensity upon ignition.

be used instead of the welding described. This group of cements includes solvents or liquids polymerizing later and the cemented parts may be dried under mechanical or gas pressure perhapswith the help of some heat.

My preferred flashlamp having an oxygen fllling at a pressure higher'than one atmosphere has also the advantage of being filled with wire or sheet metal heavier than the lamp with low or atmospheric pressure. The diameter of aluminum or magnesium wire can be increased with pressure or, if sheet material is utilized, the thickness of this sheet material can be increased. Concentrated coils and spun or woven material can be used with a suitable high pressure." A diameter or thickness of combustible material greater than .002 inch or of the order of .002

inch can be utilized. a s I a a The reason is that the heat generated on a 4. A lamp comprising a light-passing selfsupporting sealed "container of: cellulose acetate characterized by translucency and flexibility, a

combustible metal and a combustion-supporting.

gas at substantially more than atmosphericpressure within said container; and means yior instigating combustion of said metal, said gas pressure tending to retain the container inflated to maximum volume and obtaining increased lightintensity upon ignition.

5.AI lamp comprising a light-passing self-f supporting sealed container from the group of organic plastics (characterized by translucency and flexibility, a reflecting coating on a portion 1 of thewall of said container, a combustion-sup:

unit surface increases with oxygen pressure and a the maximum cross-section of combustible material is limited by its cooling eifect versusthe It the .heat

sectional area can be increased also. The eflect tain the container inflated to maximum volume r and obtaining increased light intensity upon igis a temperature increase and a combustion time This advantage of thicker combustible material is 'in addition to the faster combustion with absence oi time lag and to the decreased volume and dimensions of the lamp made It is apparent that many modifications may be made in the preferred embodiments illustrated, and accordingly, I desire only such limitations to be imposed upon my invention as are within the spirit and scope of the, following claims. I Y

I claim: s j i l. A flashlamp comprisinga casing member, a base member sealed to said casing member, conductors sealed through said base member,

combustible metal and a combustion supporting gas at substantially more than atmospheric presdecrease which results in a narrow high peak possible by the porting gas, at a (pressure substantially more than atmospheric pressure within said fcontainer, means "for combining'with said gas and thereby producing light within and emanating from said container, and. means for instigat'mg said combining, said gas pressure tending to renition; s

6. A lamp comprising a light-passing sealed container. said container comprising a closedend tubular self-supporting member from the group of organic plastics characterized by translucency and flexibility, a secondself-supporting member from this same group sealed across the open end of said flrstmember, conductors sealed through said-second member, combustible metal of said first membenconductors sealed through sure in'said casing member, means connectedto said conductors for igniting said combustible metal, said casing member comprising a trans lucent self supporting material from the group of cellulose acetate, urea-formaldehyde, phenolformaldehyde, casein, pyroxylin, shellac and rubber. a

2. A lamp comprising a light-passing self-sup- Q porting sealed container from the group of organic plastics characterized by translucency and flexibility, said container, having therein a combustible material and a combustiomsupporting gas at a pressure substantially more than atmospheric, and means for igniting said gas and prosaid second member, combustible metal in said container, and means in said container connectedto said conductors for igniting said com-' bustible metal, saidgas pressure tending to re-,

tain the. container inflated to maximum volume 1 and obtaining increased light intensity upon ignition.

8.v A lamp comprising a container of a closedend tubular light-passing self-supporting member from the group of organic plastics characterized by translucency and flexibility, a second self-supporting ember from this same group sealed across the open end of said first member," a gaseous fillingof a combustion-supportin gas substantially above atmospheric pressure in said container, conductors sealed through said second member, combustible metal in said containers, and means in said container connected to said conductors for igniting said combustible 3 metal, said gas pressure tending to retain the container inflated to maximum volume and obtaining increased light intensity upon ignition.

9. A lamp comprising a container of a closedend tubular light-passing self-supporting memher from the group of organic plastics characterized by translucency and flexibility, reinforcing ribs in said tubular member, a second member iromthis same group sealed across the open end 01' said first'member, a gaseous filling oi. an active gas substantially above atmospheric pressure in said container, conductors sealed through said second member. combustible metal-in said container, and means in said container connected to said conductors for igniting said combustible metal, said gas pressure tending to retain the container inflated to maximum volume and obtaining increased light intensity upon ignition.

MICHAEL J. NEUMANN DI: MARGITTA. 

